Disposable syringe with plunger rupture

ABSTRACT

The disposable syringe with a plunger rupture device and a washer-guide sealing barrel nozzle is supposedly safe, since the plunger breaks up and the piston is stuck an the bottom of the barrel, making impossible its reloading and avoiding the use of the product. The sequence for assembling the syringe is shown on page  12/13:    
     fitting the pressure washer to the plunger—FIG.  12.1;    
     fitting the rubber to the piston base—FIG.  12.2;    
     fitting the plunger to the piston—FIG.  12.3;    
     inserting the support bolt to the fitting of the set plunger/piston—FIG.  12.4;    
     fitting the assembled set plunger/piston into the barrel—FIG.  12.5  and  
     finally, the screening washer is sealed, sealing the syringe entirely—FIG.  12.6.    
     The device is totally manufactured with materials similar to the ones used in common syringes and available in the market. Syringes with this device can be assembled in syringes with volume of 0.5 cc, i.e., in all kinds of available syringes, with small changes due to their sizes, as shown on page  13/13.

[0001] Disposable syringes: syringes that were supposed to be discarded after their use. Unfortunately, those syringes are being re-used, as proven by the statistics. About 25% of AIDS cases are directly associated to disposable syringes.

[0002] There are several brands and models of syringes available in the market. However, no model is really disposable. They are only projected with the objective of guaranteeing the quality and sterility of the product. Therefore, it is of extreme importance that providences are taken so that these syringes can really be disposed, avoiding the burden of additional expenses to the Health System due to their re-use. The warnings “To be used only once” or “To be destroyed after the use!” printed in the packing don't guarantee that the product will be discarded. There are no secure ways of supervising the final user of the product. If each sold unit were really destroyed after its use, the cost with syringes would be ridiculous when compared with the economy generated by the reduction of Health expenses due to the sharing of disposable syringes.

[0003] This Patent of Invention is about the “Disposable Syringe with a plunger rupture device” or, more accurately, about a device of automatic action which makes the syringe be used only once. The syringe is characterized by a device that allows the charging of fluids as in any common syringe; however, when the piston has its course reversed, the pressure that the user exercises in the plunger, and, consequently, in the piston, receives a contrary pressure from the fluid. At this point, the device is triggered: the rubber suffers a deformation, expelling the support bolt from the set plunger/piston. This make the claws at the plunger lose their grip and the piston detaches itself from the plunger, getting stuck at the bottom of the barrel, making impossible a second use of the syringe.

[0004] The objective of this invention is to force the use of the syringe a single time. The breaking of the device is the warranty against a possible re-use. In order to make easier the understanding of our invention, we are enclosing a detailed description of the device. We have used a 20 ml disposable syringe as model.

[0005] Page 1/13—Components. Scale 1:2. Barrel (FIG. 1); Needle (FIG. 1.1); Plunger (FIG. 1.2) Screening washer-guide (FIG. 1.3); Support bolt (FIG. 1.4); Piston rubber base (FIG. 1.5); Rubber (FIG. 1.6).

[0006] Page 2/13—Perspective of the system after triggered. (FIG. 2);

[0007] Page 3/13—Upper view of the piston rubber base (FIG. 3). Scale 1:4;

[0008] Cut of the set rubber and base (FIG. 3.1) Piston in its normal shape (FIG. 3.2) Scale 1:4 Support bolt (FIG. 1.4) scale 1:4.

[0009] Page 4/13—Upper view of the assembled device;

[0010] Page 5/13—Upper view of the plunger (FIG. 5) scale 1:3;

[0011] A cut of the plunger (FIG. 5.1). scale 1:3;

[0012] Page 6/13—Side view of the plunger claw (FIG. 6). scale 1:3;

[0013] A better description of the action of the claw FIG. 6.1) scale 1:3;

[0014] Rubber action of the piston (FIG. 6.2 and FIG. 6.3) scale 1:3;

[0015] Page 7/13—Side view of the sealing washer-guide (FIG. 7). scale 1:2.

[0016] Upper view of the washer sealing guide (FIG. 7.1) scale 1:2.

[0017] Washer-guide in perspective (FIG. 7.2) scale 1:2. Upper view of the nozzle of the barrel (FIG. 7.3) scale 1:2.

[0018] A cut of the barrel nozzle (FIG. 7.4) scale 1:2.

[0019] Page 8/13—Upper view of the barrel nozzle (FIG. 8). scale 1:4;

[0020] Cut of the barrel (FIG. 8.1) scale 1:4;

[0021] Page 9/13—Syringe in its normal shape (FIG. 9) scale 1:2; action of the claw after expelling the support bolt and retention of the plunger claws (FIG. 9.1). scale 1:4 action of the piston rubber (FIG. 9.3) scale 1:4.

[0022] Page 10/13 (no scales). The assembled syringe as the final consumer will purchase in the market (ready for use) (FIG. 10). The process will be identical to the one of common syringes up to the point of charging of fluids (FIG. 10.1). When the pressure is reverted, i.e., when the user presses the plunger to expel the fluid, the energy will be transferred proportionally to the piston, resulting in the deformation of the rubber. This deformity will automatically expel the “support bolt” from the plunger/piston set (FIG. 10.2). Once the support bolt is expelled, the plunger loses its grip and it is disconnected from the piston, disabling the syringe (FIG. 10.3). The plunger can then be removed from the barrel totally. However, the piston will be kept at the bottom of the barrel due to the release of the rubber (FIG. 10.4). The plunger itself will become a container for the used needle (FIG. 10.5).

[0023] Page 11/13—(No scales)—Demonstration of the impossiBili ty of a second use without the sealing washer-guide. Once without the washer-guide, the plunger loses its centralization; consequently, the piston loses its perpendicularity in relation to the wall of the barrel. In the charging process, the vacuum will suck the air (FIG. 11.1) and, in the injection, the pressure of the fluid being larger than the atmospheric pressure makes the fluid flow back (FIG. 11.2), resulting in the loss of the fluid to be injected (FIG. 11.3).

[0024] Page 12/13—Sequence for assembling the syringe.

[0025] Page 13/13—Device for insulin syringes. 

1. DISPOSABLE SYRINGE WITH RUPTURE OF PLUNGER. Manufactured in resistant plastic material and sterilized according to the syringes commonly available in the market: The disposable syringe has a plunger end different from the ones available now. This plunger end is characterized by claws and is designed to increase the flexibility of the inferior end (page 9/13—FIG. 9.1). Those claws are fit into the rubber base, which has have a groove, as seen in the drawings (page 3/13—FIG. 3); the plunger will remain fastened to the piston through a support bolt, which is of capital importance for the success of the product (page 6/13—FIG. 6). The support bolt will have the same diameter as the hole, where it will be fit in +0 −0 (page 3/13—FIG. 3) in order to hold it; this way, the claws and the hole of the rubber base will completely involve the cylindrical or spherical tip of the bolt (page 6/13—FIG. 6). The user of the syringe will be able to pull the plunger normally to charge any liquid, since the support bolt will avoid the return of the claws. The plunger will offer resistance to the rupture and the set won't break up (page 10/13 FIG. 10.1). However, when the user reverts the action, i.e., when he presses the plunger to inject the fluid, the proportional pressure of the liquid against the piston will deform the rubber, displacing the support bolt automatically, disrupting the function of the support bolt (FIG. 10.2). In this stage, the plunger is disconnected from the piston (FIG. 10.3) and it will be impossible to charge new fluids (FIG. 10.4). After its use, the plunger becomes a container for the used needle (FIG. 10.5).
 2. DISPOSABLE SYRINGE WITH RUPTURE OF PLUNGER. As stated in claim #1, characterized by the flexibility of the plunger and for the lower extremity with endings in claws, cut in >45°, as shown in page 9/13 (FIG. 9.1). The claws are fixed with the aid of the support bolt (FIG. 9.2). The bolt loses its function as support bolt when it is displaced;
 3. DISPOSABLE SYRINGE WITH RUPTURE OF PLUNGER. As stated in claim #1, characterized by the rupture of the plunger. Once the plunger is discarded, it becomes an appropriate container for the supposedly infected needle, due to its hollowness. This way, it will be possible to avoid accidents with third parts in the handling of the discarded syringe (page 5/13—FIG. 5 and cut—FIG. 5.1) (page 10/13—FIG. 10.5)
 4. DISPOSABLE SYRINGE WITH RUPTURE OF PLUNGER. As stated in claim #1. Characterized by the existence of a ridge at top extremity (nozzle) of the barrel, which will wrap the washer-guide. This washer-guide sealing contains grooves in order to avoid its extraction. The washer-guide will have an internal diameter larger than the barrel diameter, enough to fit under pressure and seal the syringe. If the user forces the extraction of the washer, the washer will break up, making impossible the normal use of the syringe (page 11/13—FIG. 11, 11.1, 11.2 and 11.3; perspective view page 7/13—FIGS. 7, 7.1, 7.2 and 7.4).
 5. DISPOSABLE SYRINGE WITH RUPTURE OF PLUNGER. As stated in claim #1, the device could be manufactured in all models of syringes available in the market, including syringes of 01 ml and 0.5 ml (insulin) (page 13/13).
 6. DISPOSABLE SYRINGE WITH RUPTURE OF PLUNGER. As stated in claim #1. Considering that an user can break the washer and keep using the syringe, the plunger was designed with a minimum dimension traverse, which creates an oscillation in the handling of the plunger-piston set. This oscillation removes the perpendicularity of the piston to the barrel (page 11/13).
 7. DISPOSABLE SYRINGE WITH RUPTURE OF PLUNGER. As stated in claim #1. Although the system is identical, the tuberculin syringe of 01 cc and 0.5 cc will present a small change in the support bolt and in the claws at the end of the plunger (as shown in the page 13/13—scale 1:1, assembled syringe (FIG. 13); side view (FIG. 13.1); frontal view (FIG. 13.2); broken system (FIG. 13.3)). The support bolt will be manufactured in steel and plastic. The needle shall be manufactured in steel, with its cylindrical or flat tip made of plastic material, similar to pins available in the market (FIG. 13.4); perspective view—(FIG. 13.5). The bolt may also be manufactured in steel or any other metal (according to the standard medical-hospital norms). 